Electromagnetic pump



Fb- 8, 1949- D. 1 MlLLER 2,461,501

ELEGTROIAGNETIC PUMP Filed laren 7, 1947 Patented 4Feb. 8 1949 ELECTROMAGNETIC PUMP Donald L. Miller, Pine City, N. Y., assignmto Bendix Aviation Corporation, a corporation 'of Delaware Application mmh 7, 1941, serm No. 733.2111

2 claims. (c1. 10s-5s) The present invention relates to an electromag-V netic pump and more particularly to a piston type of pump for moving fluids such as fuel for internal combustion engines.

It is an object oi' the present invention to provide a novel electromagnetic pump which is efflcient and reliable in operation while being simple and economical in construction.

It is another object to provide such a device -in which the actuation of the piston is positively controlled by the movement of the piston itself.

It is another object to provide such a device in which the control is eiected by a mechanical connection from the piston to the controlling element.

It is another object to provide such a device in which leakage of iluid from the pump chamber direction away from the iixed contact Il is preiis prevented by a flexible packing member per manently connected to the pump cylinder and the controlling element.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing, in which: Y

Fig. 1 is a vertical substantially mid-sectional view of a preferred embodiment of the invention: and

Fig. 2 is a sectional detail taken substantially on the line 2-2 of Fig. l.

In Fig. 1 of the drawing, there is illustrated a pump cylinder I of non-magnetic material such as brass in which is slidably mounted a piston 2 oi' magnetic material such as soft iron having a passage 43 therethrough controlled by a check valve I. A spring 5 is arranged to urge the piston in a direction to eject fluid from the cylinder l, and a solenoid 6 surrounding the cylinder I is so positioned that when energized it retracts the piston 2 against the force of the spring 5.

Means for energizing the solenoid 6 is provided comprising a battery l grounded at 8 and connected through a switch 9 and leads I I and I2 to one terminal of the solenoid 6. The other terminal of the solenoid is connected by a lead I3 to a iixed contact I4 mounted on a stationary bracket I5 but insulated therefrom as indicated at I6.

A casing I'I is arranged to enclose and support y erably limited by an adjustable stop 22; and in order to secure a snap action of the control member, a compression spring 23 is located between the end of the control lever and the side of the Y casing in such manner as to urge the control lever away from the mid-position between its contact-opened and contact-closed positions.

The side oi' the pump cylinder is provided with an opening 24 adjacent the control lever permitlting the end of the control lever to enter the cylinder, and the piston 2 is provided with an elongated notch or recess 25 adapted to receive the end of the control lever I 5, the shoulders 26 and 2l formed by the ends of said recess being arranged to engage and move the control lever, as the piston reciprocates. It will be understood that the recess 25 is so dimensioned as to secure the desired length of stroke of the pump piston.

In order to prevent escape Vof iiuid from the pump cylinder l, through the opening 2l, a collar 28 is iixed to the cylinder around said opening in any suitable manner as by soldering, and a. ilexible packing member in the form of a bellows 29 of suitable elastic material is iixedly mounted at one end on the collar 28 in such manner as to provide a uid type joint. The other end of the bellows is similarly connected as by solderingto the control lever i9 adjacent its pivot whereby the opening 2l is hermetically sealed while permitting the vibratory motion of the control member.

In operation, starting with the parts in the positions illustrated in Fig. l, with the piston at the top of its stroke and the control contacts I4, 2l closed, closure of the switch S causes solenoid B to draw the piston down against the action of the spring 5 until the shoulder 2B on the piston engages the control lever I9 and swings it in a counter-clockwise direction, opening contacts I 4, 2| and thereby deenergizing solenoid I5. The momentum of the piston 2 carries the control lever I9 beyond its dead center position whereby the springv 23 is effective to hold the contact 2i against the stop 22.

Spring 5 is thereupon effective to raise the piston 2 and thereby eject the fluid above the piston into the upper part of the casing I l. When suiiicient iluid has been permitted to leave the casing through the outlet, the shoulder 2'1 of the piston 2 engages the control lever I9 and moves it in the direction to close the contacts 2|, I4, such closure taking place by a snap action b v Vlr- The swinging movement of the lever I9 in the 55 tue of the toggle compression spring 23 whereupon the actuation ofthe piston by the solenoid is repeated. s

Although but one embodiment of the invention has been shown and described in detail, it will be understood that other embodiments are possible and that changes may be made in the design and arrangement oi the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In an electromagnetic pump a cylinder of Y non-magnetic material, a piston of magnetic material slidably mounted thereo spring mean's for moving the piston in a direction to eject uid from the cylindensaid piston having a fluid passage therethrough, means preventing backward flow of fluid through said passage.. a solenoid surrounding the cylinder adapted when energized to draw the piston back against the action of said 'spring means, magnetic pole pieces surrounding the cylinder at the ends of the solenoid, a cylindrical casing of magneticmaterial surrounding and connecting the pole pieces. a bracket xed to one of the pole pieces, a ixed contact on said bracket, a second bracket xed to the interior of the casing, a lever pivoted on the second bracket, a movable contact mounted on one end of the lever in position to cooperate with the fixed contact. a lost motion mechanical connection between the other end of lever and the piston arranged to swing the lever to close the contacts when the piston approaches the end of its dismovement of the lever.

DONALD L. MILLER.

, REFERENCES CITED The following references are of record in the tile of this patent:

UNITED STATES PATENTS Number Name Y Date 1,337,388 Bradbury Apr. 20, 1920 1,783,611 Gohring Dec. 2, 1930 1,925,934 Rimstad et al Sept. 5, 1933 2,211,440 Shepherd Aug. 13, 1940 

